Kaposiform hemangioendothelioma of the breast in an adult female.

Kaposiform hemangioendothelioma (KHE) is a locally aggressive vascular tumor that usually occurs in infants. It is commonly associated with Kasabach-Merritt syndrome and lymphangiomatosis. It generally originates on the skin, later affecting deeper tissue by infiltrative growth. Although visceral involvement is very uncommon, several cases with bone, retroperitoneal, or mediastinal involvement have been described. However, to our knowledge, a KHE in breast tissue has never previously been reported. Furthermore, the development of this type of tumor in adolescents and adults is very rare. We treated a 32-year-old woman with a right breast mass that was diagnosed based on pathologic examination as a KHE. We performed operations several times because of recurrence of KHE and finally performed mastectomy despite the patient's young age.